The Globe and Mail reports in its Friday edition that the war with Iran is pushing the price of critical fertilizers higher, just as farmers across North America begin the spring planting season and are in need of crop nutrients. The Globe's Kate Helmore writes that a significant amount of all fertilizer trade passes through the 39-kilometre-wide Strait of Hormuz, which essentially shut down this week after Iran said it would "set fire" to any ships that try to pass through. Growers have been beleaguered over the past year by a series of geopolitical tensions and can ill afford higher input costs. Retailers, analysts and economists are questioning how much more uncertainty and volatility agricultural operations will be able to absorb before fertilizer demand falls, soil is depleted and harvests suffer. Nitrogen is the most critical nutrient for growing crops. The fertilizer plays a crucial role in photosynthesis, manufacture of proteins and is used to grow 50 per cent of the food consumed across the globe. It is used largely in the form of urea, an organic compound. Around 30 per cent of globally traded urea passes through the Strait of Hormuz, according to Bank of Nova Scotia. Phosphate is also in a perilous position.